[twobitshifter]

To prevent 3rd party access you need to not only host your own email but all recipients of your mail need to be self hosted as well. Unless you are providing everyone you correspond with their own account, 3rd parties will be involved.

[noduerme]

No, you just have to be aware of who you're sending to, and encrypt appropriately. I mean obviously if I send to someone @gmail, they're going to know I sent that person an email. But they can't scan my inbox for keywords.

[twobitshifter]

If someone sends you an email from gmail, that’s also in gmail, and you can’t guarantee that the sender will encrypt their message.